Loading BDF files fails

[cbrnr]

The last commit that affected mne/io/edf/edf.py (https://github.com/mne-tools/mne-python/commit/9ac6547284bbd73b4c18d7d7031042585388005c#diff-825d45683d0be02fad23614151867e02) broke it. When I load a BDF file like this, I get an error:

raw = mne.io.read_raw_edf("test.bdf")

Traceback (most recent call last):
  File "/Users/clemens/Library/Preferences/PyCharmCE2017.2/scratches/scratch_4.py", line 4, in <module>
    raw = mne.io.read_raw_edf("/Volumes/Begabungsforschung/Analysis/Data/EEG/adds/vp1/vp1_exp_eeg.bdf")
  File "/Users/clemens/Repositories/adds/mne/io/edf/edf.py", line 1229, in read_raw_edf
    exclude=exclude, preload=preload, verbose=verbose)
  File "<string>", line 2, in __init__
  File "/Users/clemens/Repositories/adds/mne/utils.py", line 728, in verbose
    return function(*args, **kwargs)
  File "/Users/clemens/Repositories/adds/mne/io/edf/edf.py", line 158, in __init__
    annotmap, eog, misc, exclude, preload)
  File "/Users/clemens/Repositories/adds/mne/io/edf/edf.py", line 564, in _get_info
    tal_channel is None and n_samps[stim_channel] != int(max_samp):
ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

However, if I set stim_channel='auto' explicitly, it works. This is strange since this is also the default value.

[larsoner]

So this is almost certainly related to the same commit/PR as #4710, but is now a new breakage mode?

It looks like these are documented clearly enough that we should be able to fix it. I can try to find time to fix it in the next week or so unless someone else beats me to it. We'll need to fix and backport to 0.15.

[cbrnr]

So this is almost certainly related to the same commit/PR as #4710, but is now a new breakage mode?

This error was introduced by 9ac6547. I don't understand why it occurs yet, because explicitly setting stim_channel='auto' should be the same as using the default - but it's not.

No need to backport, this commit was after 0.15.

[larsoner]

It is different in the reader read_raw_edf:

https://github.com/mne-tools/mne-python/blob/master/mne/io/edf/edf.py#L1154

Than in the class RawEDF:

https://github.com/mne-tools/mne-python/blob/master/mne/io/edf/edf.py#L153

Can you make a quick PR to fix it? If not I can get to it later this week.

[cbrnr]

Alright, this should be fixed in #4751